One minute with Jeff Greason

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  • 24 October 2009 | NewScientist | 27

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    What can NASA do to improve?

    NASA should have a technology road map:

    it doesnt have a plan saying, These are the

    capabilities we have today, these are the

    capabilities we want tomorrow, and how are

    we going to get there from here?

    Which cutting-edge technologies should

    NASA develop first?

    The very first element would be a technology for

    the handling and storage of propellant in space .

    If we had such a gas station it would significantly

    change the game in terms of what you could do:

    it would let you launch a much more capable,

    bigger mission with the same-size launchers. If

    you use chemical rockets, you want to be able to

    manufacture that propellant at your destination .

    That saves a huge chunk of initial mass

    because you dont have to take the propellant

    with you to get you back to Earth. Then theres a

    whole bunch of ideas for advanced space

    propulsion. An ion engine called VASIMR is a

    perfect example.

    What surprised you most in your work with

    the White Houses Augustine Committee?

    We hoped to find a way for NASA to do great and

    wonderful things within their current budget but

    we really didnt. And it wasnt for lack of trying.

    Over the long term, if youre not going to make the

    budget go up, and you want to do something

    great, you have to lower the fixed costs.

    What can NASA do to cut costs?

    There was one option which involved relying on

    expendable launch vehicles the Delta IV and

    Atlas V rockets the cost of which would be

    shared with the Department of Defense. That

    does have the potential to change the fixed

    costs of the human space flight programme.

    Is NASA still capable of inspiring

    achievements like the Apollo moon landings ?

    Its easy to say, and Ive said it myself, that we just

    dont have the NASA we used to have, so we cant

    do the things we used to do. But whatever is

    One minute with...

    Jeff Greason

    wrong or right with NASA, the quality of the

    people isnt a problem. NASA has really good,

    motivated people. One contributing factor could

    be that were not asking them to do the right job.

    But the bigger question is, do we really want to

    spend whatever it takes, hundreds of billions of

    dollars, all so we can race to plant a flag for reasons

    of national pride?

    But you dont think we should discontinue

    human space exploration?

    I think one of the most important findings that we

    made on the Augustine committee is that there is

    an underlying reason why we should be doing

    human space exploration, which is that we ought

    to extend permanent human civilisation beyond

    this planet, and that is an incredibly important

    human endeavour. Stephen Hawking calls for

    moon and Mars colonies. To my mind, I cant see

    why we wouldnt do it. Its the only way to create a

    future in which humans can live somewhere other

    than Earth. Robots will help, but you dont learn

    how to live in places by just sending robots.

    Interview by David Shiga

    One of the leading lights of the private space industry argues that NASA must keep investing in human space exploration












    Jeff Greason is CEO of XCOR Aerospace and sits

    on the USs Augustine Committee, which reviews

    NASAs plans for human space flight. He spoke at

    a recent Space Investment Summit in Boston

    grown more slowly than that

    of most non-dependent crops.

    However, contrary to what we

    would expect if pollinators were

    in decline, the average yield of

    pollinator-dependent crops

    has increased steadily during

    recent decades, as have those

    of non-dependent crops, with

    no sign of slowing.

    Overall, we must conclude

    that claims of a global crisis

    in agricultural pollination

    are untrue.

    Pollination problems may be

    looming, though. Total global

    agricultural production has kept

    pace with the doubling of the

    human population during the

    past five decades, but the small

    proportion of this that depends on

    pollinators has quadrupled during

    the same period. This includes

    luxury foods such as raspberries,

    cherries, mangoes and cashew

    nuts. The increased production of

    these crops has been achieved, in

    part, by a 25 per cent increase in

    cultivated area in response to

    increased demand for them.

    This expansion may be

    straining global pollination

    capacity, for two reasons. Demand

    for pollination services has grown

    faster than the stock of domestic

    honeybees, and the associated

    land clearance has destroyed

    much of the natural habitat

    of wild pollinators.

    The accelerating increase

    of pollinator-dependent crops

    therefore has the potential to

    trigger future problems both for

    these crops and wild plants. These

    problems may grow as decreasing

    yields of raspberries, cherries and

    the rest prompt higher prices,

    stimulating yet more expansion

    of cultivation. So although the

    current pollination crisis is largely

    mythical, we may soon have a real

    one on our hands.

    Marcelo Aizen is a researcher at the

    National Scientific and Technical

    Research Council of Argentina.

    Lawrence Harder is a professor

    of pollination ecology at the University

    of Calgary in Alberta, Canada